I'm disappointed that almost everyone posting in this thread is making suggestions about what other people should do rather than thinking of ways to contribute themselves.
I plan to open at least one PR a month adding a useful new test to Bitcoin Core, or significantly improving an existing test, with the first PR to be opened by 31 October 2018.
What do the rest of you plan to do?
newbie needs to have a track record before dictating what others could or should do, no? Let's see if you do what you said you were going to do. How many months are you going to report back to show that you have taken actual action and are more than just promises?